diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/RegAllocFast.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/RegAllocFast.cpp | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/contrib/llvm/lib/CodeGen/RegAllocFast.cpp b/contrib/llvm/lib/CodeGen/RegAllocFast.cpp index f4c076f..8d7a721 100644 --- a/contrib/llvm/lib/CodeGen/RegAllocFast.cpp +++ b/contrib/llvm/lib/CodeGen/RegAllocFast.cpp @@ -1002,11 +1002,13 @@ void RAFast::AllocateBasicBlock() { unsigned DefOpEnd = MI->getNumOperands(); if (MI->isCall()) { - // Spill all virtregs before a call. This serves two purposes: 1. If an + // Spill all virtregs before a call. This serves one purpose: If an // exception is thrown, the landing pad is going to expect to find - // registers in their spill slots, and 2. we don't have to wade through - // all the <imp-def> operands on the call instruction. - DefOpEnd = VirtOpEnd; + // registers in their spill slots. + // Note: although this is appealing to just consider all definitions + // as call-clobbered, this is not correct because some of those + // definitions may be used later on and we do not want to reuse + // those for virtual registers in between. DEBUG(dbgs() << " Spilling remaining registers before call.\n"); spillAll(MI); |
